This article examines the events surrounding the excommunication of the Birgittine monastery Marienkrone in Stralsund by the bishop of Schwerin between 1514 and 1515. It explores the turn of events from the perspective of the Birgittine connections to secular rulers and the Papal Curia. The discussion focuses on the dynamics of the excommunication in connection with the Birgittine indulgences as the primary cause for the punitive action. The article aims to discuss how a monastery and a religious order, on the eve of the Reformation, organised an international campaign to resolve a local conflict. It also demonstrates the vulnerability of religious houses in a changing religious and political climate and Marienkrone’s dependency on its patrons to give financial aid to pay fees for curial procedures in Rome. The core of the conflict between the Birgittines and the secular clergy of Stralsund was the far-reaching indulgences of the Birgittine Order that spurred competition between the religious institutions about visitors and incomes. Indulgences are here discussed as the core of the conflict and the article traces it back to the long tradition of the Birgittine Order to issue indulgences, which practice at the time of the conflict had become increasingly questioned from within the Church, which also were at the core of the Lutheran Reformation that begun in 1517, just three years after the conflict in Stralsund.